fix: Dockerfile to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-ALPINE318-EXPAT-6241039
- https://snyk.io/vuln/SNYK-ALPINE318-LIBX11-6042398
- https://snyk.io/vuln/SNYK-ALPINE318-LIBXML2-6245694
- https://snyk.io/vuln/SNYK-ALPINE318-OPENSSL-6032386
- https://snyk.io/vuln/SNYK-ALPINE318-OPENSSL-6032386

Dockerfile

@@ -178,7 +178,7 @@ CMD ["python -m gunicorn -b [::]:8000 fiesta.wsgi:application"]
 #
 # proxy image
 #
-FROM nginx:1.25.2-alpine as proxy-base
+FROM nginx:1.26-alpine as proxy-base
 
 RUN rm /etc/nginx/conf.d/default.conf